ONCOLOGY LETTERS 11: 1429-1434, 2016
Inflammatory myofibroblastic tumor with RANBP2 and ALK gene rearrangement with bland cytological features mimicking desmoid-type fibromatosis: A case report and review of the literature YU‑HUA HUANG1, YU‑FENG TIAN2 and CHIEN‑FENG LI1,3‑5 Departments of 1Pathology and 2General Surgery, Chi‑Mei Medical Center, Tainan 710; 3National Institute of Cancer Research, National Health Research Institutes, Tainan 704; 4Graduate Institute of Clinical Medicine, Kaohsiung Medical University, Kaohsiung 807; 5Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan 710, Taiwan, R.O.C. Received November 6, 2014; Accepted September 24, 2015 DOI: 10.3892/ol.2016.4082 Abstract. �������������������������������������������� Here, we present an uncommon case of inflammatory myofibroblastic tumor (IMT) involving the mesentery. The tumor was composed of loosely arranged round‑to‑spindle‑shaped tumor cells with amphophilic cytoplasm in an inflammatory and myxoid background. The mitotic activity was low (1 per 50 high‑power fields) and the tumor cells lacked cellular atypism. Immunohistochemically, the tumor cells demonstrated strong nuclear membranous staining with anaplastic lymphoma kinase (ALK). In situ hybridization for ALK gene rearrangement revealed a splitting apart of the two signals within the tumor cells. Reverse transcription‑polymerase chain reaction revealed that the tumor harbored a ran‑binding protein 2 (RANBP2)‑ALK rearrangement. IMTs are usually characterized by epithelioid‑to‑round cells featuring increased mitotic activity, occasionally demonstrating unusual tumor cells and more aggressive clinical behavior. To date, 23 IMTs have been reported with RANBP2 and ALK gene rearrangements. However, the present case demonstrated indolent cytological features, leading to a difficulty in differentiating it from desmoid‑type fibromatosis. Introduction Inflammatory myofibroblastic tumor (IMT) is a neoplasm composed of myofibroblastic and fibroblastic spindle cells, accompanied by an inflammatory infiltrate containing
Correspondence to: Dr Chien‑Feng Li, Department of Pathology, Chi‑Mei Medical Center, 901 Chunghwa Road, Yung Kang, Tainan 710, Taiwan, R.O.C. E‑mail: [email protected]
Key words: inflammatory myofibroblastic tumor, round cell, anaplastic lymphoma kinase, ran-binding protein 2
lymphocytes, plasma cells, eosinophils or neutrophils. It occurs mainly in children and young adults with a slight female predominance. Metastasis occurs in
Inflammatory myofibroblastic tumor with RANBP2 and ALK gene rearrangement with bland cytological features mimicking desmoid-type fibromatosis: A case report and review of the literature YU‑HUA HUANG1, YU‑FENG TIAN2 and CHIEN‑FENG LI1,3‑5 Departments of 1Pathology and 2General Surgery, Chi‑Mei Medical Center, Tainan 710; 3National Institute of Cancer Research, National Health Research Institutes, Tainan 704; 4Graduate Institute of Clinical Medicine, Kaohsiung Medical University, Kaohsiung 807; 5Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan 710, Taiwan, R.O.C. Received November 6, 2014; Accepted September 24, 2015 DOI: 10.3892/ol.2016.4082 Abstract. �������������������������������������������� Here, we present an uncommon case of inflammatory myofibroblastic tumor (IMT) involving the mesentery. The tumor was composed of loosely arranged round‑to‑spindle‑shaped tumor cells with amphophilic cytoplasm in an inflammatory and myxoid background. The mitotic activity was low (1 per 50 high‑power fields) and the tumor cells lacked cellular atypism. Immunohistochemically, the tumor cells demonstrated strong nuclear membranous staining with anaplastic lymphoma kinase (ALK). In situ hybridization for ALK gene rearrangement revealed a splitting apart of the two signals within the tumor cells. Reverse transcription‑polymerase chain reaction revealed that the tumor harbored a ran‑binding protein 2 (RANBP2)‑ALK rearrangement. IMTs are usually characterized by epithelioid‑to‑round cells featuring increased mitotic activity, occasionally demonstrating unusual tumor cells and more aggressive clinical behavior. To date, 23 IMTs have been reported with RANBP2 and ALK gene rearrangements. However, the present case demonstrated indolent cytological features, leading to a difficulty in differentiating it from desmoid‑type fibromatosis. Introduction Inflammatory myofibroblastic tumor (IMT) is a neoplasm composed of myofibroblastic and fibroblastic spindle cells, accompanied by an inflammatory infiltrate containing
Correspondence to: Dr Chien‑Feng Li, Department of Pathology, Chi‑Mei Medical Center, 901 Chunghwa Road, Yung Kang, Tainan 710, Taiwan, R.O.C. E‑mail: [email protected]
Key words: inflammatory myofibroblastic tumor, round cell, anaplastic lymphoma kinase, ran-binding protein 2
lymphocytes, plasma cells, eosinophils or neutrophils. It occurs mainly in children and young adults with a slight female predominance. Metastasis occurs in
